Index vs Lectrum
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Index
Organize and recall information from various sources like links, notes, and documents. Discuss complex ideas with your saved content and get answers grounded in your personal knowledge base. Capture information quickly using the share sheet and maintain control over your data.
- Save links, notes, and documents
- Organize personal knowledge
- Discuss complex ideas with saved content
- Extract readable page content
- Syncs across devices
- Delete data anytime
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Save anything. Think with everything. Index is a personal knowledge workspace for the context you do not want to lose. Share a link, note, or document from your iPhone, and it becomes part of a calm, organized brain you can return to later. ASK YOUR BRAIN Discuss complex ideas across everything you have saved. Index grounds answers in your own context and links citations back to each source. CAPTURE WITHOUT BREAKING FOCUS Use the iOS share sheet to save useful links, selected text, files, and quick notes in seconds. TURN LINKS INTO CONTEXT Index extracts readable page content, creates a concise summary, and keeps your own note beside it. STAY IN CONTROL Your account syncs across devices. Delete individual items and conversations whenever you want, or permanently delete your account and its captures, files, chats, and feedback from inside the app. Built for founders, researchers, and knowledge workers who want less friction between finding something useful and thinking with it. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://index-legal.vercel.app/privacy
Lectrum
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Lectrum is for the ideas you have once and never think about again. Write the thought down, mark how much it matters, and Lectrum brings it back to you on its own schedule. High-importance ideas return often. Medium ones return less often. Low ones never interrupt you at all — they wait at the top of your list until their time comes. CAPTURE ANYWHERE Tap +, or tap the waveform and just talk: "call the dentist tomorrow at nine" is saved with its reminder already set, and two ideas in one breath become two. Or ask Siri — "Talk to Lectrum". Share a link or a passage from Safari, Mail or Notes straight into Lectrum. Add a Control Center button and capture without opening the app. Attach a photo. Write in Markdown if you like — headings, lists, links and checkboxes all render. RESURFACING • High and Medium ideas arrive as reminders; Low ideas appear in a Resurfaced section instead • One optional daily digest gathers everything due today • Ideas you keep letting pass ease off by themselves; open or edit one and it steps back up • Set an exact delivery time per level, and quiet hours for the night • A one-off reminder on a date of your choosing, for any idea AT THE NEXT MEETING Turn on Meetings and Lectrum remembers which calendar event an idea was written in, then brings it back when you next meet the same people. Your calendar is read on this device only. ON YOUR WRIST AND YOUR HOME SCREEN On Apple Watch, raise your wrist and capture an idea by voice, scribble or typing; it lands on your iPhone understood like Talk, reminder and all, and a complication opens Lectrum ready to listen. Up Next and single-idea widgets sit on the Home Screen and Lock Screen, and they are interactive. PRIVATE BY DESIGN Lock the app with Face ID or a passcode, with auto-lock, and hide idea text from widgets and search while locked. There is no account to create, nothing to buy, no ads, and no analytics or tracking. Your ideas live on your device and sync through your own iCloud; you can also mirror them to a Markdown folder in iCloud Drive you control. Reminders follow your phone's clock, so exact times and quiet hours stay correct when you travel or the clocks change.
Screenshots
Verdict
The clearest difference is in-app purchases: Lectrum at none against Index's 2. On price, ads, 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
Both are free to download. Index sells 2 in-app purchases, starting at $9.99 per month. Lectrum asks for nothing beyond the download.
| Parameter | Index | Lectrum |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) — better | — |
| Number of ratings | 1 — better | — |
| Update frequency | — | Every 2 months |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Freemium | — |
| Devices | iPhone, iPad | iPhone, Apple Watch |
| Requires iOS | 17.0 | 17.0 |
| Further details — not scored | ||
| Size | 19 MB | 19 MB |
| Age rating | 4+ | 4+ |
| Developer | Sunset Capital, llc | Business Lion LLC |
In-app purchases
Index
- Index Pro Monthly$9.991 Month
- Index Pro Annual7 Days trial$79.991 Year
Lectrum
No in-app purchases









