Yes I would start on phonics too. My son started reading at 4 just a few months after I started teaching him. I was showing him LR every day at least once, each lesson only once. We were reading easy Sightwords readers each day. A book every day was our motto and still is. I read a page then he read the page until he got good enough to read them without my help. I actively taught him letter sounds. I didn't use reading bear but did teach him how to sound out words. We used fridge magnets to build CVC words like cat, sat, mat, fat and he learnt them as word families.
We used preschool prep sight word apps and they helped a lot. Along with their DVDs.
I have to admit the I didn't think little reader was going to do much at his age except give him a bigger bank of skills to draw on but now that he reads fluently I can see it DID help. Every now and then he will walk past my IPad, glance at the screen and determine exactly what the page is about instantly from one word of heading. Yesterday he picked "waterfall" instantly from a page showing hair styles. He read it in a nano second!
so the sight word focus must help. My two best fastest readers are the ones who got flash card exposure. The one that didn't has some bad reading habits ( like skipping word endings, guessing too often and not alot of overall interest in reading at all). Based on this I suggest doing LR continuously as long as you can. I just think at age 4 and up you need MORE than just flash cards.
Try any systematic phonics program along with easy sight word readers and sight word games. Do it EVERYDAY and you will see dramatic success.