regarding the ipad (and any tech), do a 'tech check' before bedtime. You should know all items of tech in the house so ensure all are downstairs and in charge if needed. No hiding of the ipad if you know exactly where it is downstairs.
The rest, frankly, just needs a parental backbone.
I understand the last 7 months have been very hard for all of you and it is completely understandable that you will just take the path of least resistance, the easiest option to reduce any additional stress.
However now is the time to be strong. Both for yourself and for your son. Your 7 year old needs his Mum to be "Boss". He may test to see if you can and will maintain the role of taking charge. But for him wellbeing, he needs clear boundaries and rules. Bedtime falls entirely within the realms of ^clear boundaries and rules".
Set the rules. Then stick to them. He is old enough to cope with this as straight-forward as that.
M 6 year old goes to bed at 7.30pm and my 10 year old at 8.30 - so a 7 year old would aim for the start of bedtime routine at 7.30 (toilet, teeth, story etc) with bedtime around 7.45 and the expectation that (in time) he will be asleep by 8.00pm.
So to do this - you need to stay calm and stay consistent. Rapid return any time he gets out of bed. This involves quickly turning him around, stay calm, back to bed, say "nan night", close the door and leave. Expect to need to stay upstairs and repeat this lots and lots and lots of times for the first few nights. Until he 'gets it' and gives up to stay in bed.
He is old enough to possibly try manipulating in other ways. Once he learns that getting up is not having the desired effect of a reaction from you, he will try other ways to get your attention.
Ignore anything not dangerous (like shouting, screaming, pillow hitting) as long as is not harming anyone/anything. Deal with any issues that require intervention with minimal words and interaction. Importantly staying quiet and calm throughout. Just a chirpy "Nan night" (to show you are unaffected by his tantrums) when you leave the room.
It will be hard work for a week or so. Therefore pick your timing well and have support available if possible.