[Closed] Cheap bike computers

Moon/Stick time.

I'm an avid MTBer but have bought a cheap road bike for training due to proximity to decent trails, and for workouts in the summer house.
Budget unfortunately doesn't run to a smart trainer, but a friend has leant me some rollers that I'm using the bike on when I can't get outside.

I'd quite like a cycle computer with cadence stuff to try and structure workouts properly on the rollers, and as a bonus it'd be handy to have out on the road I guess. Are the el cheapo chinese ones like this:
https://www.amazon.co.uk/Suaoki-Transmission-Speedometer-Backlight-Resistant/dp/B01AVQY74W/ref=sr_1_2?ie=UTF8&qid=1483445256&sr=8-2&keywords=cadence+cycle+computer
actually any good? Or will it just die after seconds?

Budget is very tight, but my ideal list would be:
Cadence sensor
Speed sensor
Wireless would be nice
Ability to link up with Strava on Android phone would be handy (no idea if this is even doable?!)
As cheap as possible. I mean cheap, cheap, not 'considerable richer than you' cheap. £100 is not cheap. That's half the cost of a Tacx Flow...)

Any pointers appreciated - very new to all this, and the whole training lark in general. (Previously my training was 'just riding til I drop 5 nights a week', but location and fatherhood now prevent this)