Comparison

Fill In Studio vs AestraBook

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Fill In Studio

This app helps fitness studios and gyms fill empty class spots by connecting them with local clients seeking last-minute bookings. Easily post classes, create discounted deals, and manage all your bookings and payments securely.

Highlights
  • Studio dashboard for bookings and revenue
  • Post classes with details and photos
  • Create flash deals for last-minute openings
  • Manage class bookings and attendee lists
  • Secure Stripe Connect payouts
  • Instant notifications for new bookings
Features
Read full description

Fill In Studio is the companion app for fitness studios and gyms on the Fill In platform. Post classes, manage bookings, create flash deals, and grow your business — all from your iPhone. THE FILL IN OPPORTUNITY Every empty spot in your class is lost revenue. Fill In connects you with a community of fitness enthusiasts actively looking for last-minute classes near them. When you have openings, they're ready to book. HOW IT WORKS 1. POST your classes with details, pricing, and photos 2. SET your "Fill In" price (discounted rate for last-minute bookings) 3. CREATE flash deals when you want to fill spots fast 4. WATCH bookings roll in from nearby fitness seekers Fill In handles everything — payments, notifications, and customer communication. You focus on delivering great workouts. KEY FEATURES • STUDIO DASHBOARD — See your bookings, revenue, and active deals at a glance • POST CLASSES — Create classes with descriptions, photos, pricing, and capacity • FLASH DEALS — Offer time-sensitive discounts to fill empty spots quickly • CLASS TEMPLATES — Save your recurring class types for one-tap posting • MANAGE BOOKINGS — View who's coming to each class • EDIT & CANCEL — Update class details or cancel with automatic attendee notifications • ANALYTICS — Track performance, popular classes, and earnings over time • STRIPE CONNECT — Secure, automated payouts directly to your bank account INSTANT NOTIFICATIONS When you post a class or flash deal, Fill In automatically notifies nearby fitness enthusiasts who have enabled alerts. Your class gets visibility exactly when it matters. STRIPE CONNECT PAYOUTS Fill In uses Stripe Connect for secure, reliable payments. After completing a quick onboarding process, you'll receive payouts directly to your bank account. Track your earnings in the app and on the Stripe dashboard. WHO IS FILL IN STUDIO FOR? • BOUTIQUE FITNESS STUDIOS looking to fill last-minute openings • YOGA & PILATES STUDIOS wanting to reach new clients • GYMS offering specialty classes • INDEPENDENT INSTRUCTORS who teach at multiple locations • FITNESS ENTREPRENEURS growing their client base SUPPORTED CLASS TYPES - Yoga (all styles) - Pilates (mat & reformer) - HIIT & Circuit Training - Barre - Indoor Cycling / Spin - CrossFit - Strength Training - Dance & Cardio - Boxing & Martial Arts - And more! SIMPLE PRICING Fill In takes a small platform fee only when you get paid. No monthly fees. No setup costs. No risk. GET STARTED 1. Download Fill In Studio 2. Create your studio profile 3. Complete Stripe Connect onboarding 4. Post your first class It takes just minutes to set up. Start reaching new clients today! Need help? Contact our studio support team: studios@getfillin.com Learn more at: getfillin.com/studios

About

AestraBook

This platform helps independent business owners manage appointments and showcase their services online. Clients can easily view offerings, check availability, and book services through a customizable page.

Highlights
  • Customizable booking page
  • Service and pricing management
  • Appointment scheduling
  • Deposit collection
  • Availability control
  • Client experience enhancement
Read full description

Aestra is a modern booking platform built for independent business owners who want a better way to manage appointments and present their brand online. Create a beautiful, customizable booking page where clients can view your services, check your availability, review your policies, and reserve appointments in just a few taps. Whether you are a hairstylist, braider, barber, or esthetician, Aestra helps you stay organized while giving clients a polished booking experience that feels professional from the first click. With Aestra, you can: Create a custom booking page Showcase your services, pricing, availability, policies, and brand style in one easy-to-share link. Manage appointments from your phone View upcoming bookings, track client details, and keep your schedule organized wherever you are. Set services, prices, and durations Add your service menu with clear descriptions, pricing, deposits, and appointment lengths. Collect deposits for appointments Require deposits to help secure bookings and reduce last-minute cancellations or no-shows. Control your availability Set when you are available, block off time, and make it easier for clients to book the right appointment. Share a better client experience Give clients a clean, simple way to browse services, choose a time, and book without messy back-and-forth messages. Aestra is designed for independent business professionals who want their booking system to feel as polished as their work. Download Aestra and start building a booking experience your clients will love.

Screenshots

Fill In Studio4 screens
AestraBook3 screens

Verdict

The call

Fill In Studio and AestraBook are too close to call on the numbers: across 9 compared parameters — price, rating, ratings volume and update cadence among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for Fill In Studio against 5.0 for AestraBook. Both are backed by a comparable volume of ratings — 1 and 2 respectively.

UpkeepUpdate frequency

Fill In Studio ships an update every 2 weeks, AestraBook every 9 days. The most recent releases landed on October 10, 2026 and October 24, 2026 respectively.

ScorecardNo meaningful differences
Fill In Studio versus AestraBook: the parameters behind the verdict, then further details
ParameterFill In StudioAestraBook
PriceFreeFree
Rating5.0 (1 ratings)5.0 (2 ratings)
Positive reviews—100.0% of reviews
Number of ratings12 — better
Update frequencyEvery 2 weeksEvery 9 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS14.0 — better15.1
Further details — not scored
Size61 MB43 MB
Age rating4+4+
DeveloperFill In LLCDVNTND LLC

Customer experience

Fill In Studio

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

AestraBook

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Fill In Studio

No in-app purchases

None

AestraBook

No in-app purchases

Questions

Is Fill In Studio free?
Fill In Studio is free to download, with no in-app purchases.
Is AestraBook free?
AestraBook is free to download, with no in-app purchases.
Which has better reviews, Fill In Studio or AestraBook?
Fill In Studio and AestraBook are both rated 5.0 out of 5 on the App Store, from 1 and 2 ratings respectively.
Do Fill In Studio or AestraBook have ads?
Neither Fill In Studio nor AestraBook shows ads.
Which is updated more often, Fill In Studio or AestraBook?
Fill In Studio ships an update every 2 weeks, and AestraBook every 9 days. Most recently, Fill In Studio was updated on October 10, 2026 and AestraBook on October 24, 2026.

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