Cathode was the iconic retro terminal on iOS, phosphor glow, scanlines, optional barrel distortion, the lot. Secret Geometry built it around the aesthetic, and that aesthetic was the point. ShellDrop comes at the terminal from the other side: a modern flat client aimed at people who want to keep a tmux session attached to Claude Code on a headless Mac Mini and not think about how the type looks.
The two apps were built for genuinely different jobs, and that is about where the overlap ends. Side-by-side anyway.
| ShellDrop 5 | Cathode | |
|---|---|---|
| Availability | On the App Store, actively updated | Removed from the App Store, discontinued around 2017 |
| Pricing model | Free. No in-app purchases. | Was a one-time purchase (historically about $4.99); no longer sold |
| Platforms | Native on iPhone and iPad, Vision Pro with version 5, macOS coming soon | iPhone, iPad (no longer available) |
| Aesthetic | Modern flat dark, custom terminal colours | CRT phosphor, scanlines, distortion |
| Account required | No | No |
| Telemetry | None | None on record |
| SSH | Yes | Yes (SSH only) |
| Paste a screenshot into the terminal | Yes. Any image, multi-image; agent reads them on the server | No |
| Attach a file from Files or Photos | Yes. Files, photos or video; uploads over SSH, path lands at the prompt | No |
| Voice dictation | Built in. On-device Apple speech free, or your own Groq key. | Not a listed feature |
| Public-key auth (SSH keys) | Ed25519 and Secure Enclave P-256 | RSA / DSA, pasted in as plaintext; no Secure Enclave |
| SFTP | No | No |
| Tmux single-finger scroll | Yes | Standard scroll |
| iPad layout (incl. 13" iPad Pro M4) | Universal app, full-canvas landscape, centred toolbar | iPad supported (historic) |
| Custom command shortcut | One Tap toolbar button | Snippets |
| Latest release | v5.0 (2026) | None since around 2017 |
Copy an image anywhere on the phone and paste it into the session. Your agent reads it on the server. Multi-image paste works too. The same toolbar has a paperclip button for files: pick one from Files, or a photo or video from the library, upload over SSH, and the path lands at the prompt. Cathode never offered anything like either, and the app is no longer sold. For anyone feeding screenshots to a coding agent all day, that is the gap between one paste and a five-step detour.
The clipboard works the other way too. Ask the agent to write something, tell it to copy the result, and it lands on the phone's clipboard ready to paste into another app. It is opt-in and takes about ten seconds to set up. Terminal text selection is now a dedicated mode: toggle it on, long-press a word, drag the handles, copy. And Nerd Fonts (FiraCode and JetBrains Mono) ship bundled, so the glyphs nvim and LazyVim rely on render the way they should.
Single-finger swipe through tmux scrollback. Esc, Ctrl-C, arrow keys, Shift-Tab, and a tmux detach button on the toolbar at all times. Built around the workflow of leaving a coding agent running in tmux and checking in from a phone.
ShellDrop generates P-256 keys inside the iPhone Secure Enclave. Private key cannot be exported. Ed25519 generation and paste-import of unencrypted OpenSSH keys also supported.
No up-front cost.
ShellDrop adds Voice Drop, a built-in mic on the keyboard toolbar. It transcribes on-device with Apple speech at no cost, or through your own Groq API key for whisper-large-v3-turbo, and drops the words at the cursor without sending Return. Dictating a long prompt to an agent is the kind of input a phone keyboard is worst at, and it is where ShellDrop puts the least friction.
Version 5 also added custom key bindings for the keyboard toolbar: create your own Tmux-aware keys in Settings, Ctrl plus a key with an optional follow-up, and arrange them like any stock key.
This was the whole reason Cathode existed and it was genuinely well executed. The CRT effect was faithful, the typography fit the look, and the app earned its place as a small piece of design history. If you ever wanted your terminal to feel like a Mac SE running NetHack at 2am, Cathode was the app.
Cathode shipped a stack of bitmap fonts, screen curvature and glow, static and flicker filters, tube-bounce animations, and even retro sound effects. On iOS it connected out over SSH, and the vintage-hardware feel was the reason to run it. ShellDrop has its own look but does not try to be a CRT. Worth knowing: there is a separate Cathode for Mac that is a local terminal with no SSH; only the now-removed iOS app did SSH.
Phosphor colour, scanline intensity, screen curvature, ambient hum, the dials were all there for anyone who wanted to tune the look.
No. Cathode has been removed from the App Store worldwide, the developer's website now redirects to a domain-for-sale page, and there has been no update since around 2017, so it can no longer be bought. It remains a beloved piece of design history. ShellDrop is a current, maintained SSH client if you need one today.
No longer. Cathode was discontinued and hasn't had an update since around 2017. It was well loved for its CRT aesthetics, it just isn't being worked on or sold any more.
It runs tmux over SSH like any vt-compatible terminal. It is not built around tmux the way ShellDrop is.
Yes. Free on the App Store, no in-app purchases, no subscription, no account.
You can set custom terminal colours for text and background. It does not do a CRT shader with scanlines and curvature; that vintage look was Cathode's speciality.
ShellDrop. tmux scroll, dedicated Esc / Ctrl-C / arrow keys, background keep-alive, One Tap for firing commands at the agent.
ShellDrop is on the App Store. Universal iPhone and iPad, iOS 17+. Free, no subscription.
