Comparison

Spine vs Understory

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

Head to head
About

Spine

Organize your reading life by creating tiered lists of books you've finished. Track your reading progress, see what friends are reading, and discover personalized recommendations.

Highlights
  • Create book tier lists
  • Track reading progress
  • Follow friends' reading habits
  • Discover personalized recommendations
  • Import Goodreads library
  • Log start and finish dates
Features
Read full description

Your profile is a tier list. Rank every book you finish, follow friends, and find what to read next. Import your Goodreads library in a few taps. Follow your friends and see what they're reading, create a blend, share books that mattered, recommend books. [ READING LOG ] Mark books read, currently reading, or queued. Note when you started, when you finished, and what you thought. [ TIER LISTS ] S, A, B, C, D. Easily drag-and-drop your favorites into a tier list. [ FRIENDS ] See what your people have read. Let them know what you've read and what you think about it. [ DISCOVER ] Personalized recommendations based on what you’ve read, rated, and exactly what you're specifically looking for. [ IMPORT ] Easily bring your Goodreads library over. Mr. Bezos won't miss you.

About

Understory

This app helps you track your reading progress, set goals, and build a consistent reading habit. It features a unique plant aesthetic and allows you to grow real-world trees by meeting reading objectives. Connect with friends, share recommendations, and view insightful reading statistics.

Highlights
  • Log reading progress and books
  • Set reading goals and streaks
  • Grow real-world trees by meeting objectives
  • Connect with friends and join book groups
  • Share book recommendations
  • View reading statistics and insights
  • Organize custom reading lists
Features
Read full description

Understory is a reading tracker, book tracker, and social reading app designed to help you track books, log reading progress, set reading goals, and stay consistent. Whether you’re organizing your bookshelf, building a reading habit, or joining a book group, Understory brings together everything you need in one place with a fun plant aesthetic. Join the Understory bookish community to build a better reading habit and build a better world! GROW REAL-LIFE TREES: Watch your garden bloom in Understory and meet monthly objectives to grow real-world trees! Visit friends’ gardens daily to help their trees grow! INTERACT WITH FRIENDS: Join book groups where you and your friends can read different books! Like and comment on reviews in the social feed! TRACK YOUR READING: Review your books with half stars, audiobook tags and private reads! Manage your library with custom reading lists including a Did Not Finish (DNF) list! LEVEL UP YOUR READING: Improve your reading habit with leaderboards for books read, reading streaks, and XP level! Earn XP by logging reading and interacting with other users! SHARE BOOK RECS: See your friends’ favorite and highly rated books and share book recommendations directly with your friends! SEE YOUR STATS: Get insights on your reading history and social interactions through shareable stats and graphs and our signature Library Card graphic! Understory is perfect for readers who want to: - Track books and reading progress in one place - Build a daily reading habit and reading streak by growing a fun garden that doesn’t feel like a chore - Log books, reviews, and ratings (with half stars!) - Organize a TBR (to be read) list - Track audiobooks and ebooks - Join a social book community - Discover new book recommendations Terms of Use: https://www.understory-app.com/terms-of-use Privacy Policy: https://www.understory-app.com/privacy-policy Content and Copyright Policy: https://www.understory-app.com/content-copyright-policy

Screenshots

Spine4 screens
Understory4 screens

Verdict

The call

The clearest difference is in-app purchases: Spine at none against Understory's 6. On price, rating, review sentiment and ratings volume 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

Both are free to download. Understory sells 6 in-app purchases, starting at $4.99 per month. Spine asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for Spine against 4.9 for Understory. Both are backed by a comparable volume of ratings — 86 and 63 respectively. Written reviews are what separate them: 100% of Spine's written reviews are positive against 96% of Understory's.

UpkeepUpdate frequency

Spine ships an update weekly, Understory every 9 days. Both last shipped on November 9, 2026.

Scorecard2 real differences · 8 level
Spine versus Understory: the parameters behind the verdict, then further details
ParameterSpineUnderstory
PriceFreeFree
Rating5.0 (86 ratings) — better4.9 (63 ratings)
Positive reviews100.0% of reviews — better95.8% of reviews
Number of ratings86 — better63
Update frequencyWeekly — betterEvery 9 days
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFreemium
DevicesiPhoneiPhone
Requires iOS17.016.4 — better
Further details — not scored
Size42 MB213 MB
Age rating4+12+
DeveloperTanner FlakeUnderstory Studios LLC

Customer experience

Spine

All ratings86 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews21 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Understory

All ratings63 ratings
Positive96.8%
Neutral3.2%
Negative0.0%
Written reviews24 reviews
Positive95.8%
Neutral4.2%
Negative0.0%

In-app purchases

None

Spine

No in-app purchases

6 purchases

Understory

Subscriptions4
  • Understory Premium1 Month trial$4.991 Month
  • Understory Premium - Monthly$4.991 Month
  • Understory Premium1 Year trial$49.991 Year
Show 1 more
  • Understory Premium - Yearly$49.991 Year
One-time2
  • Streak Freeze$0.99
  • Streak Restore$0.99

Questions

Is Spine free?
Spine is free to download, with no in-app purchases.
Is Understory free?
Understory is free to download, with in-app purchases available.
Which has better reviews, Spine or Understory?
Spine is rated higher. Spine averages 5.0 out of 5 from 86 ratings, while Understory averages 4.9 from 63 ratings.
Do Spine or Understory have ads?
Neither Spine nor Understory shows ads.
Which is updated more often, Spine or Understory?
Spine ships an update weekly, and Understory every 9 days. Most recently, Spine was updated on November 9, 2026 and Understory on November 9, 2026.

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