Vaptur needs at least 5% of total free memory to be available for recording.  Due to the heavy processing used for dual screen processing, the App needs enough space for the rough video to be stored before it is processed for playback and sharing after initial recording.  If you don’t have enough memory, check out the post on how to regain memory to allow recording.

The calculation relies on the system to tell the app how much space is available and what the total file system size is, then divides the former by the latter and makes sure that’s greater than 5%.

For example,  2.3 GB of free memory may not be sufficient depending on the size of your device’s memory.

2.3 / 16 GB = 14% = sufficient

2.3 / 64 GB = 4% = not sufficient

2.3 / 128 GB = 2% = not sufficient