Add alternative to swipe gesture opening of extended functions tab

[ghost]

I use gesture navigation, and this makes it hard for me to open the tab of additional functions in the right (sin, cos etc.). Either use an alternate solution to opening this tab such as a button, or detect if gesture navigation or button navigation is used. I don't know if detecting this is possible, so if it isn't add a settings toggle.

[prathameshmm02]

There is a button to open the sliding panel but because of API changes in a newer version of SlidingPaneLayout it's not working. I'll try to find a workaround for this.