Shoppix app is it worth it

I've been using it for years and I usually get a £10 Amazon voucher every 2-3 months. It's a great app.

Definitely worth it. Points for receipts, for the odd survey which take 10 seconds, and if you qualify for emailing receipts there's a few easy ways to add daily ones to your quota without purchase.

Edit: no good really for expense tracking but great for the vouchers back (edited)

Just signed up but due to demand I'm on a waiting list which can take anything up to 6 months or more to be accepted.

I don't think it will help you if you are trying to keep a track of your expenses but you will be able to collect points towards vouchers.
Huyu does add up your receipts and will show you your monthly spending but they only accept the big supermarkets so you will not be able to scan any other high street shop. Huyu is also better I think in collecting points towards voucher but you can scan receipts on both app to collect points.
As for price changes, I'm not aware of any app that will help with that

Very good app - it’ll take a while to make some money but takes seconds to upload pics of receipts. Surveys are very brief and gives you chance to earn more points through ‘scratch cards’.

Pretty good, I've had £10 so far.