When a relationship begins to fail, they say trust is the first causality. And with trust gone, in an age of mobile digital devices, there's an app for that. As more and more of people's lives are encompassed and controlled by their smartphones, they have become a more significant tool that both enables infidelity and cheating and allows the indiscretions to be brought to light.
Sometimes the consequences are inadvertent. It is unlikely that Apple developed the capability for their iPhones and iPads to be located as a means of discovering spouses cheating behavior before a divorce, but it can be quite effective in that role.
Other apps are specifically designed to either afford cheaters cover, allowing them to eliminate all trace of incriminating texts, sexts and to bury them behind innocuous looking apps. Some apps will allow a search through a spouse's phone for evidence of their bad behavior.
As the capabilities escalate, the law often lags behind. Some of the tracking or searching features could brush up against anti-stalking or wiretapping laws. Which could potentially make the activity criminal, depending of the party's relationship and the ownership of the devices.
Some couples are even having "digital-privacy" clauses added to their prenuptial and postnuptial agreements. These contractual agreements would prevent the use of digital evidence obtained from electronic devices like phones to be used in matrimonial dissolution proceedings.
The Atlantic story notes that if suspect your spouse is cheating and you decide to gather electronic evidence, you must do it properly. Even though the Fourth Amendment only applies to the government, and not private individuals, there are other laws that may control these matters and violations can render the evidence inadmissible.
As with many matters related to family law, before you do anything, you may wan to consult an attorney.
The Atlantic, "The Adultery Arms Race," Michelle Cottle, October 14, 2014