Comparison

TheGrey.app vs PDF Studio

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

Head to head
About

TheGrey.app

Features
Read full description

When the Same Thought Keeps Circling Not a crisis. Not a problem that needs solving. Just the same thought, going around once more, still hovering there. THEGREY exists for this state. When a thought keeps circling with no way out — and you don't need a way out yet. Not meditation. Not therapy. Not a mood tracker. No questions about how you feel. No suggestions. No record. 【 Why do you need THEGREY? 】Not a feature list. The reality you're living right now: • The same thought won't stop before sleep: your body is exhausted but your brain refuses to land, the thought grinding in the dark on repeat. • Walking into a place brings something back: the space itself is the trigger, old memories spiraling again without warning. • A date or anniversary arrives and the thought returns: time's inertia brings regret back automatically, no reason needed. • Shallow breathing, physical tension, thought follows: physiological anxiety feeds mental drain, the thought accelerating with your heartbeat. 【 Three entry points, three sources of circling 】 • THIS DAY | Time-triggered: circular thoughts triggered by time or date. Time seems to stand still. • THE SPACE | Space-triggered: circular thoughts triggered by location or setting. This space won't let the feeling go. • THE BREATH | Rhythm-triggered: circular thoughts triggered by rhythm or stress. The circling that happens between breaths. 【 Seven content invariants, strictly observed 】No second person · No action directive · No future tense · No causal framing · No self-comfort · No shareability design · No implied next step. No journal. No history. No progress report. Enter. Stay. Leave. Built on THE GAP Framework. Compliant with GAP-NLP-1.0.

About

PDF Studio

Features
Read full description

PDF Studio is the all-in-one PDF app that works entirely on your device. No account, no ads, no tracking — your files never leave your iPhone or iPad. READ & MARK UP • Fast, smooth reader with search, bookmarks and a page thumbnail grid • Highlight, underline, strike through and draw with Apple Pencil or your finger • Add text, shapes, arrows, sticky notes and a date stamp • Sign with your finger and reuse saved signatures • Custom stamps, Night and Sepia modes, a clean Reading View and Read Aloud SCAN & CREATE • Scan documents with the camera and clean up the edges • Turn photos into a PDF • Make scans searchable with on-device OCR CONVERT • PDF to Word, plain text or images • Images to PDF • Grayscale a PDF to save ink and shrink the file ORGANIZE • Merge, split, reorder, rotate, insert and delete pages • Compress, and batch-compress or merge many PDFs at once • Crop margins, extract images and add Bates numbers • Compare two PDFs side by side and highlight what changed PROTECT • Add or remove a password • Permanently redact text — even every match of a word at once • Watermarks and page numbers YOUR LIBRARY • Star favorites for quick access and search every PDF at once • Fill in forms • Save to Files / iCloud Drive, plus a Home Screen widget for one-tap scanning • Back up your whole library to one file and restore it on another device 100% ON-DEVICE PRIVACY Everything happens on your device. PDF Studio collects no data — no ads, no tracking, ever. That's the whole point. PDF Studio Pro unlocks every tool with no limits. Every Pro feature works 3 times free — upgrade yearly or once for lifetime. Terms of Use (EULA): https://birsoftware.com/terms.html

Screenshots

TheGrey.app3 screens
PDF Studio4 screens

Verdict

The call

The clearest difference is update cadence: TheGrey.app at every 3 days against PDF Studio's weekly. TheGrey.app also leads on iOS requirement (16.0 vs 18.0). On price, ads, in-app purchases and device support 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. TheGrey.app sells 1 one-off in-app purchase and PDF Studio sells 2 in-app purchases, starting at $9.99 per year. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

TheGrey.app ships an update every 3 days, PDF Studio weekly. The most recent releases landed on October 1, 2026 and October 14, 2026 respectively.

Scorecard2 real differences · 4 level
TheGrey.app versus PDF Studio: the parameters behind the verdict, then further details
ParameterTheGrey.appPDF Studio
PriceFreeFree
Update frequencyEvery 3 days — betterWeekly
AdsNoNo
In-app purchasesYesYes
DevicesiPhone, iPadiPhone, iPad
Requires iOS16.0 — better18.0
Further details — not scored
Size1 MB6 MB
Age rating4+4+
DeveloperHsieh ChiaMingBirkan Aksoy

In-app purchases

1 purchases

TheGrey.app

One-time1
  • The Grey Platinum$2.99
2 purchases

PDF Studio

Subscriptions1
  • PDF Studio Pro$9.991 Year
One-time1
  • PDF Studio Pro (Lifetime)$24.99

Questions

Is TheGrey.app free?
TheGrey.app is free to download, with in-app purchases available.
Is PDF Studio free?
PDF Studio is free to download, with in-app purchases available.
Do TheGrey.app or PDF Studio have ads?
Neither TheGrey.app nor PDF Studio shows ads.
Which is updated more often, TheGrey.app or PDF Studio?
TheGrey.app ships an update every 3 days, and PDF Studio weekly. Most recently, TheGrey.app was updated on October 1, 2026 and PDF Studio on October 14, 2026.

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