## Quick Verdict The best Summer Arc 90-day challenge app depends entirely on your psychological response to tracking. ViviDiary is ideal for a balanced approach, combining emoji-based mood logging with light Focus routines so you can track your emotional state alongside your goals. Habitify works best for strict, data-driven habit tracking, while Notion offers the ultimate DIY template customization. If you prefer a rigid, zero-excuses approach, the official 75 Hard app remains the standard, though it lacks the flexibility of modern modular trackers. ## What is the TikTok Summer Arc Trend? If you have scrolled through any social feed recently, you have likely seen the 2026 Summer Arc trend. Running typically from June to September, the Summer Arc is a 90-day self-improvement challenge focused on a holistic "full life upgrade." Unlike older, zero-compromise challenges, the Summer Arc balances physical fitness, mental health, skill development, and recovery. Because of this flexibility, users are migrating away from rigid apps that force a complete restart if a single daily task is missed. Instead, the market has shifted toward customizable trackers that allow for streak recovery and softer, personalized goals. We have tested dozens of [viral TikTok wellness apps](/compare/viral-tiktok-wellness-apps-june-2026-comparison) to see which ones actually hold up to daily use over a 90-day period. Below is the breakdown of the top contenders for your Summer Arc. ## Quick Comparison: Top 90-Day Challenge Apps of 2026 Before we dive into the specifics, here is how the top apps stack up against each other.

App	Primary Focus	Streak Mechanics	Privacy & Storage	Pricing
ViviDiary	Mood & Light Goals	Gentle Personal Bests (No guilt/pressure)	Cloud-stored (Supabase), de-identified text	Free / $2.99/mo or $11.99/yr
Habitify	Data-Driven Habits	Strict Streaks & Completion Rates	Cloud-synced	Free / ~$39.99/yr
Notion	DIY Systems	Customizable (Whatever you build)	Cloud-synced	Free (Personal)
75 Hard App	Rigid Discipline	Fail = Back to Day 1	Cloud-synced	$4.99 one-time

![A smartphone displaying a comparison of the best summer arc 90 day challenge apps on a wooden desk](https://images.unsplash.com/photo-1512314889357-e157c22f938d?auto=format&fit=crop&w=1200&q=80) ## ViviDiary: Best for a Balanced, Mood-Aware Arc When evaluating summer arc vs 75 hard tracker apps, the biggest differentiator is how an app handles failure. ViviDiary is a modular mood and life tracker built on the premise that your goals should support your mental state, not stress you out. Instead of treating habits as a pass/fail exam, ViviDiary uses an opt-in Focus module consisting of Routines and Todos. Routines are simply things you want to notice and keep up with, while Todos are one-off tasks. There are no pressure-style streaks, no traffic-light progress UIs, and absolutely no "you missed today" guilt notifications. Because mood is the only required input (everything else, including the 22 manual emoji modules and Focus tracking, is toggled off by default), you get a clear picture of how your 90-day challenge is actually affecting your mental health. If you want to see if your new gym routine is actually making you happier, this is the [mood tracker with habit tracking](/reviews/mood-tracker-with-habit-tracking-review) you need. From a technical standpoint, ViviDiary operates on a privacy-first architecture. Data is cloud-stored via Supabase, and diary text is de-identified before any external or AI processing occurs. Privacy here is achieved through strict data minimization and de-identification. ### Who Should Choose ViviDiary - Users who want a [forgiving approach to habit tracking](/inside/why-we-killed-strict-streaks-designing-forgiveness-habit-trackers). - People who want to correlate their daily habits with their mood patterns via the weekly Mirror feature. - Anyone prioritizing [summer mental health](/journal-guide/summer-mental-health-check-in-prompts) alongside physical goals. - Users looking for a high-value free tier (includes unlimited mood logging, 3-month archive, and up to 3 Routines / 5 Todos). ## Habitify: Best for Pure, Data-Driven Streaks If your version of the Summer Arc requires knowing exactly what percentage of your goals you completed this week, Habitify is the tool for the job. Habitify is unapologetically data-centric. It provides detailed charts, completion rates, and strict streak counters. For a certain type of user, seeing a 45-day streak is the only thing getting them out of bed for a 6 AM run. The app is well-designed, syncs across all platforms seamlessly, and integrates heavily with Apple Health and Google Fit. However, this strictness is a double-edged sword. If you get sick on day 46 and miss your habits, watching that streak reset to zero can be incredibly demotivating. ### Who Should Choose Habitify - Data nerds who love charts, graphs, and completion percentages. - Users motivated by the pressure of maintaining a long, unbroken streak. - People who are solely focused on habit execution rather than emotional tracking. ![Data charts and graphs on a mobile app interface representing summer arc trend tiktok 2026 apps](https://images.unsplash.com/photo-1551288049-bebda4e38f71?auto=format&fit=crop&w=1200&q=80) ## Notion (Templates): Best for the DIY Optimizer Notion is not a dedicated habit tracker; it is a blank canvas. For the 90-day challenge participant who wants to track water intake in ounces, daily reading in pages, and workout intensity on a custom 1-10 scale, Notion is unmatched. The TikTok community has flooded the internet with custom Summer Arc Notion templates. You can build relational databases that connect your daily habits to your macro life goals. The downside? Friction. When you are tired at 11 PM, opening a complex database to check off a box takes significantly more effort than tapping a single button in a dedicated app. If you are interested in [building your own tracker](/reviews/obsidian-vs-dedicated-journal-apps), you have to be honest with yourself about whether you will actually maintain the system you build. ### Who Should Choose Notion - System builders who want 100% control over their tracking parameters. - Users who want to combine their 90-day challenge tracker with their project management and note-taking systems. - People willing to trade daily convenience for deep customization. ## The 75 Hard App: Best for Strict, Unforgiving Rules We cannot discuss the best summer arc 90 day challenge apps without mentioning the app that started the modern tracking craze: the official 75 Hard app. This app does one thing: it tracks the specific, unchangeable rules of the 75 Hard program (two workouts, a gallon of water, 10 pages of reading, a diet, no alcohol, and a progress picture). It does not care about your mood, it does not offer flexibility, and if you miss a single item, it forces you to press a button that resets your progress to Day 1. It is brutal by design. For users who need an uncompromising drill sergeant in their pocket, this $4.99 one-time purchase does exactly what it advertises. But for the modern Summer Arc trend—which emphasizes balance and recovery—this app is often too rigid. ### Who Should Choose The 75 Hard App - Users specifically doing the 75 Hard program, not a modified Summer Arc. - People who require a zero-excuses environment to succeed. - Those who prefer a one-time purchase over a subscription model. ## Verdict: Which Tracker Fits Your 90-Day Goals? The shift from strict boot-camp challenges to the more balanced Summer Arc trend in 2026 requires a shift in the tools we use. If you want a tracker that adapts to your life and helps you understand how your new habits impact your mental well-being, **ViviDiary** is the logical choice. Its modular design and forgiving Focus routines make it sustainable for the full 90 days. If you are driven purely by metrics and completion rates, **Habitify** provides the best dashboard. If you want to engineer a highly specific tracking system from scratch, go with **Notion**. And if you want to ignore the Summer Arc entirely and stick to the original, uncompromising gauntlet, the **75 Hard app** is waiting for you.

90-Day Challenge

Best Summer Arc 90-Day Challenge Apps (2026 Comparison)