private void pullData() {
        File tmp = new File(backup);
        tmp.mkdirs();
        tmp.delete();

        info("Your device will ask you for permission to backup files. Do NOT enter a password, just accept.");

        String messages = "";
        try {
            Process p = Runtime.getRuntime().exec(new String[] {"adb",
                    "backup", "-f", tmp.getPath(), "-noapk", "-noshared",
                    "-nosystem", app});

            messages = Util.streamToString(p.getErrorStream()) + " " + Util.streamToString(p.getInputStream());
            p.waitFor();
        } catch(Exception e) {
            messages += " " + e.getMessage();
        }

        if(!tmp.exists() || tmp.length() <= 0) {
            error("Something went wrong, we didn't get the backup: " + messages);
            return;
        } else {
            info("Successfully downloaded a backup.");
        }
    }