VOSIS Pro vs sqsl Latch
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
VOSIS Pro
Transform images into unique sounds and compose visual music. This tool offers advanced filters and MIDI control for experimental sound design and creative audio manipulation.
- Image to sound conversion
- Advanced image filters
- MIDI keyboard support
- Customizable presets
- Unlimited recording
- Video file loading (iPad/Desktop)
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VOSIS is a synthesizer combining audification of greyscale pixel data with several image filters. It is a tool for image sonification, visual music composition, and experimental sound design. The audification of pixel luminance values creates shape-timbre relationships. Pixel scan rate is controlled in terms of note interval, octave, and scale to give varying pitch between image regions. The ADSR envelope allows one to play images as a non-linear sequence of pitches with varying wavetable/timbre. VOSIS Pro adds several features to VOSIS useful for sound designers and musicians: Save and load custom presets, connect a MIDI keyboard and play regions with keys, map any control and region positions to MIDI CC, unlimited recording and screen mirroring with no watermark, downsampling/blur/sharpen, and tremolo filters, subdivide large regions into step sequence mode, load video files (iPad and Desktop versions only). Visit vosis.app for sound example, demo videos, and user guide!
sqsl Latch
This app is a conceptual MIDI controller and sequencer for creating drone, textural, and soundscape synthesizer patches. It allows for sending MIDI notes, pitch bend, and CC values with advanced looping and parameter modulation features. Save and recall your setups for later use.
- MIDI note, pitch bend, and CC output
- 16 groups with assignable MIDI channel and color
- 8 assignable Continuous Controllers per group
- Looper for recording and shuffling note phrases
- Adjustable phrase playback speed and synchronization
- Parameter modulation via internal randomizer
- Smooth parameter transitions with LAG control
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sqsl Latch is a conceptual MIDI controller and sequencer designed for working with evolving drone, textural or soundscape synthesizer patches. It can send out MIDI notes, pitch bend and CC values. There are 16 groups split into 2 banks (a, b, c, … p). Groups have assignable MIDI channel, color and 8 Continuous Controllers (CC). When user touches one of the pads, note is activated and is held on until new touch (on the same pad) is registered. Left slider controls the velocity of note to be activated. Every group has a looper able to record note state changes - phrases. Order and velocity of recorded notes is automatically shuffled after phrase restarts (can be optionally prevented by activating group’s LOCK button). Phrase playback speed is adjustable (CLOCK and DIVIDER parameters). Phrase can be synchronised - set to restart automatically with previous group's loop. Synchronisation can be set to happen on every pass, every second, third... up to 16th and can be set to be ignored randomly (probability setting 0-100%). Group parameters can be adjusted using sliders or modulated by internal randomiser with adjustable range (RANGE and RANGE 2 parameters) and speed (per group LAG control - left-most slider). Apart user definable CCs, each group has following MIDI parameters: MOD (mod wheel), BEND (pitch bend), VOL (volume), EXP (expression), PAN (pan), FOOT (foot controller), TOUCH (aftertouch/channel pressure). Group parameters related to phrase playback are: CLOCK (resolution and playback speed), SYNC with divider (loop synchronization), NOTE SKIP (randomly skipping notes events 0-100%), SYNC SKIP (randomly skipping sync events 0-100%), DIVIDE (integer group's CLOCK divider), LOOP (loop or one-shot setting), SHIFT (degree offset with selected scale). LAG can be applied to parameter changes - when new value is selected, change does not happen immediately but value is transitioned smoothly based on LAG time (left-most slider). Setup setting (CC numbers, channels, colors, and MIDI output) are saved and recalled when app is restarted. Loops, CC values, parameters and their modulation states can be written to preset positions for later recall. For detailed description visit https://www.seqsual.com/latch Important notes: - Latch does not make any sounds on its own, it generates MIDI messages (notes, pitchbend and CC values). - Latch does not synchronise to incoming external MIDI clock. - Latch was designed for full-size iPads and is not recommended for iPad Mini users.
Screenshots
Verdict
The clearest difference is price: VOSIS Pro at $7.99 against sqsl Latch's $19.99. VOSIS Pro also leads on rating (4.6 vs 3.7) and device support (4 vs 1). On review sentiment, ratings volume, update cadence and ads 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
VOSIS Pro costs $7.99 and sqsl Latch $19.99 up front. Neither carries in-app purchases, so what you see is what you pay.
VOSIS Pro holds the better App Store score, 4.6 against 3.7. Both are backed by a comparable volume of ratings — 7 and 3 respectively. Written reviews split almost evenly too, at 67% and 67% positive.
VOSIS Pro ships an update every 3 months, sqsl Latch every 5 months. The most recent releases landed on October 27, 2026 and September 26, 2026 respectively.
| Parameter | VOSIS Pro | sqsl Latch |
|---|---|---|
| Price | $7.99 — better | $19.99 |
| Rating | 4.6 (7 ratings) — better | 3.7 (3 ratings) |
| Positive reviews | 66.7% of reviews | 66.7% of reviews |
| Number of ratings | 7 — better | 3 |
| Update frequency | Every 3 months — better | Every 5 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Paid |
| Devices | iPhone, iPad, iPod, Mac — better | iPad |
| Requires iOS | 13.0 — better | 15.5 |
| Further details — not scored | ||
| Size | 12 MB | 4 MB |
| Age rating | 4+ | 4+ |
| Developer | Life Orange LLC | Michal Macura |
Customer experience
VOSIS Pro
sqsl Latch
In-app purchases
VOSIS Pro
No in-app purchases
sqsl Latch
No in-app purchases








