Surprisingly Effective in Our Case
My 5 year old just started Level 13 on Lexia Core5 up from Level 2 from the beginning of the school year, and his reading has absolutely skyrocketed mostly because of this app. He's reading entire books with ease now. Previously, we just couldn't make progress using Khan Academy or other attempts at reading. He always seemed afraid to read, even though his phonics level was fairly advanced. Now he's reading with a lot of confidence. The reason why Lexia works for him, imho, is because of the way it shows progress which motivates completion of bite sized lessons. As someone who grew up playing a lot of JRPG video games, the concept of grinding and accumulating experience points is very similar. I agree with another reviewer who praised the gamification aspect of the app.
Every level has 10 sections consisting of about 80 pie slices / lessons in total. A lesson can take 2 to 20 minutes (or longer...). My kid loves seeing the slices fill up and feels very accomplished whenever he moves up a level. Note that it can be close to unforgiving. If you make more than 1 mistake during the lesson, usually, it will go more in depth regarding what you got wrong, and if you screw that up, then it will pound you into submission. That way, you can't just fake your way through it. I'm a big fan of this, even though it can be very frustrating for my kid. I just remind him making mistakes is a part of learning. The only lesson I didn't like had something to do with syllable separation. It was basically the only one I gave any help with because it barely made sense to me and absolutely not to him.
Make sure your device isn't too old, as the app can be dreadfully slow in that case. My kid worked on an iPad Mini 2 (obtained around 2015) for a lot of it, and some of the lessons that required dragging were extremely painful, as he knew what the answer would be but would accidentally put it in the wrong place, starting a sublesson (sometimes sub-sublesson) that he didn't need to do. A lot of tears there. That being said, we unfortunately let our kid watch a lot of Youtube (especially when sick - darn pandemic), so doing a Lexia lesson or 3 (or Math lesson) has been required before a large chunk of watching, even on the weekends. The constant practice has been very helpful, and my kid knows he has to focus and get to work to be able to get any fun screen time.
PreK: Level 1
My kid's teacher has been able to provide customized lessons for the parts that he's been struggling in, so that's been extremely helpful. I had bought the home version earlier in the year, but it was unnecessary, as my kid gets it through his school. If you want to change the level for the home version, you'll have to contact Lexia Support, who have been very responsive.
How I Use It
Public School provided app used in class and at home for a 5 year old in Kindergarten