Monitoring, logging and protection on a cell phone
Everyone knows that with technology and a more advanced way of interaction, also comes a higher risk of personal information leakage. Sure, it can be useful in some occasions, but having a tool that has even a small chance to be used in unethical purposes, will be used as such. So the best way to protect users from mobile monitoring is to make it impossible to get suspicious media and apps on your cell phone. Apple made a smart move, a few months ago, when they said no to FBI's order to allow tracking on their devices, because by doing that there will be also a way for others to do it.
The most common way to protect yourself against phone monitoring is to download apps and media only from secure sources. For Microsoft Windows OS devices that would be the Microsoft Store, for Apple phones and tablets that would be the iTunes Store and for Android OS devices, the Google Play Store. But even without using other app stores, there is a chance to be compromised, because there are apps that have hidden features, like using your phones camera, without needing your permission. If the app does that, you will be able to see it at the "App needs to access" list, that comes up when you download it. In case there are some suspicious terms, like using your messages, camera, identity information (which can be taken from Facebook and almost any other app) or even using your GPS, then you will be doing better without that app.
You won't probably find any problems on apps that consider escorts or beautiful ladies from http://www.eros.com, but you will do so with another app that is highly popular, it is called Clean Master. This app needs permission to access to your camera, personal information, identity, device ID and call information, GPS and even photos, media and files at any time they want, and if you don't accept it, you won't be able to download it. Why does a cleaning app that does nothing but clean your RAM, need access to all of that? The media term can be excused by the feature to clean your similar pictures, but the camera one can't. It also needs to know about your identity and collects information on where you have been and what you have done on http://uk.eros.com/england/london/, this smells like phone monitoring.
In order to have a strong protection, you can do also a few more steps, and there are different for Android and iOS devices. There are no possibilities for unwanted apps to get on your iPhone, unless it is Jailbroken, and to see if it is, you can simply look for the Cydia app on your phone. If it is there then you have a reason to be concerned. But there is a way to hide that icon, with SBSettings which can be found by swiping from left to right when you are on the status bar. Upgrading firmware will reverse the jailbreak, so you will be protected again.
Android devices are at higher risk to be monitored, and there is no 100% secure way to make sure there are not. You can simply check if there are any apps installed on your phone that you don't know about, if you find any - uninstall them. Always make strong passwords and look after any weird behavior, like the screen going on for no reason, or the phone unlocking or connecting to WiFi by itself. If you see any of these signs than the best solution is to back up your data and to do a restore, install a security app like F-Secure after doing that, to make the protection higher from that point.