Cracked tile, grout coming out, loose tile, and showers that leak. We find out why it failed before we fix it, so it does not fail again.
A cracked tile is usually a symptom. The floor under it flexes, or it was set without full coverage, or a joint that needed room to move did not have it. Replace the tile without fixing that and it cracks again.
A leaking shower is the same. New grout does not fix a leak, because grout is not waterproof. If water is getting behind the tile, the fix is at the waterproofing, and sometimes that means taking the shower down.
If you have leftover tile from the original job, find it. Matching old tile is the hardest part of most repairs. If there is none, we will go over the options once we have seen it.