While some apps help you save money, others have a way of encouraging you to spend more.

Changing how you connect with these types of apps by deleting them, not downloading them in the first place or limiting your interaction with them can help you rein in your spending.

Subscription-based apps. Many subscription services and boxes have corresponding apps. And you may feel inclined to sign up for a subscription if you can easily manage your membership from an app.

But automatic subscriptions are dangerous because consumers tend to continue using (and paying for) them, as opposed to canceling when they're done, said Susan Weinschenk, CEO of the Team W, a consulting company.

"If it requires action to make it stop, then we're less likely to actually take that action and make it stop," Weinschenk said.

To save, stay away from subscriptions apps in the first place. Or, use apps to fight apps. For example, Weinschenk suggests setting up alerts to remind you when a free trial is expiring — before you're charged.

Shopping apps. When consumer psychologist Kit Yarrow interviewed shoppers about how they feel when getting a good bargain, they've likened it to coming in first in a race. "There's just a winning feeling," Yarrow said.

Deal-centric apps, such as those for certain stores, bring those feel-good bargains straight to you via your smartphone. But tempting sale notifications can encourage more shopping, which may mean it's better to delete those retail apps altogether.

Another strategy? Weinschenk said she's downloaded a store's app, redeemed a coupon offer and then uninstalled the app just as easily as she installed it.

But if you're disciplined, you can keep the apps, said Casey Taylor, a partner in Bain & Co.'s retail practice. Take advantage of the savings within shopping apps, but also monitor how much you're spending in them.

Social media apps. The products you see in your social media feed — whether from retailers or friends — could encourage you to buy things you otherwise would not.

But deleting social media isn't an option for many. Instead, be aware that Instagram and Facebook will present you with buying opportunities. Be conscious that marketing is constantly targeted at you, and "you're being hunted, stalked, chased down," Yarrow said.

Even when you're not paying money for these apps, Yarrow said you're paying with your attention.

Rewards apps. Rewards program apps, whether for a grocery store, airline or coffee shop, typically function in much the same way. The more customers spend, the more rewards they unlock.

Taylor said it can almost feel like a game. For example, in the Starbucks app, "You earn stars that you can then burn for rewards," she says. If you're a disciplined customer, you could save money. Be careful not to let climbing the tiers of a reward system lead you to spend more in the process.

With any app, simply be aware of the potential dangers. Pause and recognize your tendency to overspend before it happens.

Courtney Jespersen is a writer at NerdWallet. E-mail: courtney@nerdwallet.com. Twitter: @CourtneyNerd.