Could you possibly allow for credits to be used to unlock the widget? Or could you possibly consider a separate transaction (at a reduced price) that solely unlocks the widget?
The only reason I use Muslim Pro is for prayer times as I use other apps for everything else. I, and surely many others too, cannot really justify paying £3.99 just to use the widget! I would gladly pay around 69-99p for the widget while leaving all other features locked. Otherwise, I would be happy to trade in some of my free credits.