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.