Is it permissible to use a sensitive device placed on the prayer rug to count the number of rak'ahs, whether it is on top of the rug or underneath it, knowing that it counts the number of prostrations and affects the worshiper's interaction and devotion (khushu')?

The worshipper is required to abandon whatever distracts him from devotion in his prayer. The Prophet, peace and blessings be upon him, changed his garment that distracted him. Prayer is an intimate communion with Allah, not a difficult act of worship fraught with much forgetfulness. Forgetfulness and absentmindedness are incidental and there is no harm in them. Indeed, the Prophet, peace and blessings be upon him, forgot and legislated the prostration of forgetfulness (sujood as-sahw). A device that monitors forgetfulness is not beneficial for someone afflicted with obsessive whispers (waswas) or frequent forgetfulness. Rather, a Muslim should prepare for prayer and empty his heart for it, and rid himself of the devil's whispers through remembrance (dhikr). If he forgets, he should build upon what is most likely correct and prostrate for forgetfulness, thereby humiliating the devil. Therefore, these devices should not be used. Instead, strive for what benefits Muslims.