Unless you're able to hack into the cellphone someway and are then able to remotely upload spyware software to the cellphone then no there's no other way to legit and legally add spyware to someone's cellphone.
You can install cellphone tracking software on cellphones but you must have access to the cellphone and permission to install the cellphone tracking software.
There's no other way legally to remotely install spying software on someones cellphone though.