I've used Squeegee for the past couple of years and it's fantastic now, despite a rocky start.
I've paid £9.80 per month so far but its just gone up to £15 per month for the base version. Although I just bought a year subscription at the old price for £98 so won't be paying the new price for a while.
I find it's a little complicated. Saying that, I haven't tried other apps so it may not be more complicated than the average.
Also it's complication comes mainly from its vast array of features, the layout and interface are great. It just does a lot of stuff.
Their support I've found is very good and they have live tutorials showing you how to use it.
In its early days it was plagued with bugs as features were getting churned out so rapidly, but the development has become more steady, careful and professional and I don't have any worries on that front now.
It's great especially if you have a lot of electronic payments, gocardless etc, if you text customers reminders, professional invoice generation. Some exciting features coming soon such as linking with your bank so you don't need to mark payments off, a new customer portal and automatic notifications.