Mobile App Development for Donation Collection

Developing a Mobile App for Donation Collection

Donation collection apps—separate fintech category with non-trivial requirements. Key difference from standard eCommerce: donations often recurring, amounts arbitrary (including "custom"), user must see exactly where money goes—otherwise trust drops.

Payment Types and Implementation

One-time donation—standard payment via provider. User enters sum, clicks button, sees result.

Recurring donation—user subscribes to monthly deduction. Implemented via recurring payments: on first payment, provider returns card token, server then initiates deductions on set day.

// iOS: Stripe recurring donation setup
import StripePayments

// Step 1: create SetupIntent on server for card save without payment
// Step 2: confirm with STPPaymentHandler
let params = STPConfirmSetupIntentParams(
    paymentMethodParams: cardParams,
    clientSecret: setupIntentClientSecret
)

STPPaymentHandler.shared().confirmSetupIntent(
    params,
    with: self
) { [weak self] status, setupIntent, error in
    switch status {
    case .succeeded:
        // setupIntent.paymentMethodID—save on server
        self?.saveRecurringMethod(setupIntent?.paymentMethodID)
    case .failed:
        self?.showError(error?.localizedDescription)
    case .canceled:
        break
    @unknown default: break
    }
}

Apple Pay / Google Pay for one-time donations—lowest friction. User doesn't enter card details manually:

let request = PKPaymentRequest()
request.merchantIdentifier = "merchant.com.yourcharity.app"
request.countryCode = "RU"
request.currencyCode = "RUB"
request.supportedNetworks = [.visa, .masterCard]
request.merchantCapabilities = [.capability3DS]
request.paymentSummaryItems = [
    PKPaymentSummaryItem(
        label: "Help Animals",
        amount: NSDecimalNumber(string: donationAmount)
    )
]

Custom Amount: UX Nuances

"Custom amount" field—frequent error source. Issues:

• User enters "1000.5" or "1 000" with space—normalize to Decimal
• Provider minimum limit (most—10 ₽ or 1 $)
• Max limit without 3DS

// Android: custom amount normalization
fun parseAmount(input: String): Result<Long> {
    val cleaned = input
        .replace(",", ".")
        .replace(Regex("\\s"), "")
        .trim()

    return try {
        val decimal = cleaned.toBigDecimal()
        if (decimal < BigDecimal("10")) {
            Result.failure(Exception("Minimum—10 ₽"))
        } else if (decimal > BigDecimal("150000")) {
            Result.failure(Exception("Sums over 150,000 ₽ require verification"))
        } else {
            Result.success((decimal * BigDecimal("100")).toLong()) // kopecks
        }
    } catch (e: NumberFormatException) {
        Result.failure(Exception("Enter valid amount"))
    }
}

Transparency: Fund Usage Report

Users donate more when seeing concrete goal and progress. "Fundraising progress bar"—target vs current.

// Android: Jetpack Compose progress indicator
@Composable
fun FundraisingProgress(
    current: Long,
    target: Long,
    modifier: Modifier = Modifier
) {
    val progress = (current.toFloat() / target.toFloat()).coerceIn(0f, 1f)
    val animatedProgress by animateFloatAsState(
        targetValue = progress,
        animationSpec = tween(durationMillis = 800)
    )

    Column(modifier) {
        LinearProgressIndicator(
            progress = animatedProgress,
            modifier = Modifier.fillMaxWidth().height(8.dp),
            trackColor = MaterialTheme.colorScheme.surfaceVariant,
            color = MaterialTheme.colorScheme.primary
        )
        Row(Modifier.fillMaxWidth(), horizontalArrangement = Arrangement.SpaceBetween) {
            Text("${formatAmount(current)} ₽ raised")
            Text("of ${formatAmount(target)} ₽")
        }
    }
}

Tax Deductions and Documents

For charities often need tax deduction form generation. Server logic: aggregate user payments for year, generate PDF. App just shows "Download Receipt" button.

Timeline Estimates

Basic version (one-time donations, card + Apple/Google Pay, history): 3–5 weeks. Recurring subscriptions—another 1–2 weeks. Fundraising progress bars—another 1 week. Pricing is calculated individually.