Acorns (Android, iOS) takes micro-investing mobile, grabbing the spare change from your purchases and investing it into exchange-traded funds (ETFs) to slowly build up seed money for your future. Once you sign up with your bank account or card details, Acorns provides you with a questionnaire to flesh out your financial situation and goals, and then the app will recommend a mix of ETFs for you to invest in. Every time you make a purchase with your linked card or account, Acorns takes the spare change (rounding up to the nearest dollar) to invest, building up your portfolio over time. Users can also manually set up one-time investments and recurring investments. Rather than charging you per transaction, Acorns charges a nominal monthly fee of $1 a month for accounts less than $5,000, or 0.25 percent per month for accounts greater than $5,000.