Comparison

Observer Pro vs Flex Performing Arts

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

Head to head
About

Observer Pro

This app helps advanced astronomers and astrophotographers plan their observing sessions. It predicts object visibility, factoring in local obstructions, and provides weather forecasts. Manage observing lists and favorite sites to maximize your stargazing time.

Highlights
  • 14,000+ deep sky objects with photos
  • Local horizon profile measurement
  • Object visibility prediction charts
  • Featured object recommendations
  • Favorite observing site management
  • Astronomical weather forecasts
Features
Read full description

Observer Pro is an indispensable app for advanced astronomy observing and astrophotography planning. No more guessing when that galaxy emerges from behind that tree. No more estimating how many hours you'll be able to image an object. Observer Pro gives every astronomer the info they need to make the most of their observing right at their fingertips! What astronomers are saying: "Every astronomer with an iPhone should own this app!" - Astronomy Technology Today magazine "Observer Pro is the most impressive astronomy app that I have tried out. I enthusiastically commend it to you!" - Tom Mote, Professor Emeritus, Astronomy "I have been using it since the day it first became available and I cannot live without it now." - Sedat B., Cloudy Nights forum Feature highlights: • Over 14,000 deep sky objects included, all with closeup reference photos. No need to download anything after install! Sorting and search make it easy to sift through all of them to find which objects belong on your observing list. • Measure your local horizon profile in minutes with your iPhone. • Unique charts completely take the guesswork out of predicting object visibility. Your house, trees, mountains, or any other obstructions are completely factored in to all visibility charts. • New to astronomy? The Featured object list shows a list of objects specific to your location and local horizon that are great for observing right now. • Keep a list of your favorite observing sites, each with their own local horizon profile. Compare object visibility between sites to find the best spot to setup your scope. • There's a lot to observe! Observer Pro gives you a place to maintain a list of your favorite objects as well as an observing list that you can take with you to the eyepiece. • 7Timer! astronomical weather forecasts for your observing sites are viewable without leaving Observer Pro. They give you the outlook on cloud cover, seeing, transparency, and more. • Check out the in-app help to learn more about how to use the many features that come with Observer Pro. Keep up-to-date with the latest news at the Observer Pro blog: http://observer.pro/blog

About

Flex Performing Arts

Features
Read full description

Welcome to Flex Performing Arts - It's always a great day to "Flex Your Muscles and Point Your Toes" The Flex Performing Arts app allows you to manage your account with ease, register for classes, and special events. You'll also receive important notifications about class changes, closings, registration openings, special announcements, and upcoming events. The Flex app is an easy-to-use, on-the-go way to access everything Flex has to offer right from your smartphone.

Screenshots

Observer Pro4 screens
Flex Performing Arts4 screens

Verdict

The call

The clearest difference is price: Flex Performing Arts at Free against Observer Pro's $13.99. Flex Performing Arts also leads on update cadence (every 5 weeks vs every 6 months). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

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

Flex Performing Arts is free to download; Observer Pro costs $13.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Observer Pro ships an update every 6 months, Flex Performing Arts every 5 weeks. The most recent releases landed on October 8, 2026 and October 2, 2026 respectively.

Scorecard2 real differences · 8 level
Observer Pro versus Flex Performing Arts: the parameters behind the verdict, then further details
ParameterObserver ProFlex Performing Arts
Price$13.99Free — better
Rating4.6 (49 ratings) — better—
Positive reviews79.2% of reviews—
Number of ratings49 — better—
Update frequencyEvery 6 monthsEvery 5 weeks — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaid—
DevicesiPhoneiPhone, iPad — better
Requires iOS16.416.0 — better
Further details — not scored
Size241 MB72 MB
Age rating4+4+
DeveloperJoshua BuryFlex Performing Arts

Bugs and requests

Observer Pro

Reported bugs

10 issues
  • App crashes when selecting catalog groupings (Galaxy, Planetary Nebulae, etc.)
  • iOS keyboard doesn't dismiss on iPad after clicking Done
  • Observer lists and custom data disappearing after app closure
  • Search feature missing in version 1.4
  • Continuous crashes since recent updates
Show 5 more
  • Horizon drawing feature unreliable - drifts while drawing
  • Menu items on far right side of screen unresponsive
  • Incompatibility with iOS 8 (historical)
  • App crashes on startup with certain iOS versions
  • Weather feature broken

Requested features

16 requests
  • iPad native app with landscape mode support
  • Search functionality restoration/improvement
  • Export observer lists to other apps (Sky Safari, etc.)
  • Support for planets, comets, and asteroids
  • Observing notes and session logging
Show 11 more
  • Field of view/scope focal length comparison
  • Color object photographs
  • Additional catalogs (Sharpless, etc.)
  • Moon visibility in sky view
  • Azimuth-based sorting for telescope positioning
  • Filter options for object types
  • Cross-device syncing between iPhone and iPad
  • Print functionality for observing plans
  • User-created custom catalogs
  • Screen auto-rotation support
  • Weather forecast integration

Flex Performing Arts

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Observer Pro

No in-app purchases

None

Flex Performing Arts

No in-app purchases

Questions

Is Observer Pro free?
Observer Pro costs $13.99, with no in-app purchases.
Is Flex Performing Arts free?
Flex Performing Arts is free to download, with no in-app purchases.
Do Observer Pro or Flex Performing Arts have ads?
Neither Observer Pro nor Flex Performing Arts shows ads.
Which is updated more often, Observer Pro or Flex Performing Arts?
Observer Pro ships an update every 6 months, and Flex Performing Arts every 5 weeks. Most recently, Observer Pro was updated on October 8, 2026 and Flex Performing Arts on October 2, 2026.

Other comparisons