I'm saving up for a snap on like @davidoft has. It was whizzy and didn't give you a boot every time you needed to align the dizzy up with the timing scale and crank notch.
Mine seems alright, first time I used it, it showed I didn't need to adjust my timing which had previously been set with a mates Snap On timing light. Probably won't last as long though.
I just bought this one, used it for the first time last night, works great. £12 + delivery. https://www.ebay.co.uk/itm/AccuSpar...gnition-Timing-strobe-lamp-Light/192734447180