Which is the best Clash Royale Mod for Android

A friend told me there has no real mod for Clash royale, but when i searched Clash Royale Mod on google, there goes many result:

Some mods do not need root, some mods  can Get Unlimited Gems,  some provide moded server. In all of them , the most poplular one is Clash of Lights S2 APK, i haven't seen this before,  it says: 

 Clash of Lights s2 is a COC Private Server with the best Experience Starting Items:
- Gold: 1.000.000.000
- Elixir: 1.000.000.000
- Dark Elixir: 1.000.000.000
- Gems: 1.000.000.000 

then i download it,  follow the instruction:

 How to install Clash of Lights S2

STEP 1
Go to Settings. Scroll down and tap on Security then on Unknown sources.

STEP 2
If necessary, click OK.

STEP 3
Download APK file. After the APK downloaded install it, then wait until it completes. All you have to do now is to open the game and enjoy. 

but it didn't run in my phone, is there any Clash royale mod you have used and can be used. please recommend.