What it does
Fastin is a mobile app designed to help users with intermittent fasting for weight loss and other health benefits. It doesn't just provide a timer; it creates a personalized fasting and lifestyle plan. The app's core function is to guide the user through a detailed onboarding process to understand their goals, current habits, and health status, and then generate a tailored plan with specific recommendations for fasting windows, water intake, and physical activity.
Where it shines
Fastin's onboarding process is its standout feature. It excels at making the user feel like they are receiving a bespoke service. The process begins with a clear visual promise of transformation (00:02) and transitions into a comprehensive quiz. A particularly engaging moment is the body part selection screen at 01:04, where users tap on an illustration to highlight their target areas. However, the most effective part is the "Your Personal Plan" summary screen at 01:25. This screen synthesizes all the user's quiz answers into a tangible, data-driven plan, effectively justifying the app's value before the paywall is even shown.
UX highlights
- Immediate Value Proposition: The app opens with a compelling before-and-after visual, immediately setting expectations about the primary benefit.
- Interactive Data Entry: Instead of static forms, the app uses smooth, wheel-style pickers for height (00:43) and weight (00:50), making input feel fluid.
- Comprehensive Quiz: The onboarding quiz asks about motivations, focus areas, diet, and even health conditions, which builds confidence that the resulting plan will be well-suited to the user.
- Visual Goal Setting: The body target screen at 01:04 uses an interactive diagram, which is more intuitive and engaging than a simple checklist.
- Anticipation Building: A dedicated "Customizing your plan" animation (01:22) creates a moment of anticipation before the plan is revealed.
- Pre-Paywall Summary: The plan summary (01:25) acts as a powerful value statement, showing a projected weight loss graph, BMI, and daily goals before asking for a subscription.
Monetization & growth
Monetization is handled through a hard paywall presented at the end of the onboarding flow at 01:34. There is no free trial offered. The paywall presents three options: a weekly plan, a 3-month plan, and a lifetime "Permanent Member" plan. The lifetime option is highlighted as a "Limited time offer" to create urgency. The app also breaks down the cost of two plans into a daily rate (e.g., 0,71 € / day) to make the price seem more manageable. The core strategy is to build up a high degree of perceived value through personalization before making the subscription request.
Who it’s for
This app is clearly targeted at individuals who are new to or need guidance with intermittent fasting. The detailed, step-by-step onboarding suggests it's for users who want a structured plan rather than just a simple tool. The focus on specific goals like weight loss, energy, and longevity, combined with questions about diet and exercise, indicates it's for people looking for a holistic approach to their health, not just a fasting timer.
Notes & opportunities
While the onboarding is strong, it is also quite long. Users in a hurry might drop off. The lack of any social proof elements like testimonials or star ratings during onboarding is a missed opportunity to build trust. Furthermore, the weight loss projection on the summary screen (01:26) is very specific (e.g., 134.6 lbs). While motivating, this could set potentially unrealistic expectations that might lead to disappointment if not met precisely. Adding a disclaimer or showing a range could manage expectations better.